drivers/gpio/gpio-ep93xx.c

   1 /*
   2  * Generic EP93xx GPIO handling
   3  *
   4  * Copyright (c) 2008 Ryan Mallon
   5  * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
   6  *
   7  * Based on code originally from:
   8  *  linux/arch/arm/mach-ep93xx/core.c
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2 as
  12  *  published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/io.h>
  19 #include <linux/gpio.h>
  20 #include <linux/irq.h>
  21 #include <linux/slab.h>
  22 #include <linux/basic_mmio_gpio.h>
  23
  24 #include <mach/hardware.h>
  25 #include <mach/gpio-ep93xx.h>
  26
  27 #define irq_to_gpio(irq)        ((irq) - gpio_to_irq(0))
  28
  29 struct ep93xx_gpio {
  30         void __iomem            *mmio_base;
  31         struct bgpio_chip       bgc[8];
  32 };
  33
  34 /*************************************************************************
  35  * Interrupt handling for EP93xx on-chip GPIOs
  36  *************************************************************************/
  37 static unsigned char gpio_int_unmasked[3];
  38 static unsigned char gpio_int_enabled[3];
  39 static unsigned char gpio_int_type1[3];
  40 static unsigned char gpio_int_type2[3];
  41 static unsigned char gpio_int_debounce[3];
  42
  43 /* Port ordering is: A B F */
  44 static const u8 int_type1_register_offset[3]    = { 0x90, 0xac, 0x4c };
  45 static const u8 int_type2_register_offset[3]    = { 0x94, 0xb0, 0x50 };
  46 static const u8 eoi_register_offset[3]          = { 0x98, 0xb4, 0x54 };
  47 static const u8 int_en_register_offset[3]       = { 0x9c, 0xb8, 0x58 };
  48 static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
  49
  50 static void ep93xx_gpio_update_int_params(unsigned port)
  51 {
  52         BUG_ON(port > 2);
  53
  54         writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
  55
  56         writeb_relaxed(gpio_int_type2[port],
  57                 EP93XX_GPIO_REG(int_type2_register_offset[port]));
  58
  59         writeb_relaxed(gpio_int_type1[port],
  60                 EP93XX_GPIO_REG(int_type1_register_offset[port]));
  61
  62         writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
  63                 EP93XX_GPIO_REG(int_en_register_offset[port]));
  64 }
  65
  66 static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
  67 {
  68         int line = irq_to_gpio(irq);
  69         int port = line >> 3;
  70         int port_mask = 1 << (line & 7);
  71
  72         if (enable)
  73                 gpio_int_debounce[port] |= port_mask;
  74         else
  75                 gpio_int_debounce[port] &= ~port_mask;
  76
  77         writeb(gpio_int_debounce[port],
  78                 EP93XX_GPIO_REG(int_debounce_register_offset[port]));
  79 }
  80
  81 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
  82 {
  83         unsigned char status;
  84         int i;
  85
  86         status = readb(EP93XX_GPIO_A_INT_STATUS);
  87         for (i = 0; i < 8; i++) {
  88                 if (status & (1 << i)) {
  89                         int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
  90                         generic_handle_irq(gpio_irq);
  91                 }
  92         }
  93
  94         status = readb(EP93XX_GPIO_B_INT_STATUS);
  95         for (i = 0; i < 8; i++) {
  96                 if (status & (1 << i)) {
  97                         int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
  98                         generic_handle_irq(gpio_irq);
  99                 }
 100         }
 101 }
 102
 103 static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
 104 {
 105         /*
 106          * map discontiguous hw irq range to continuous sw irq range:
 107          *
 108          *  IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
 109          */
 110         int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
 111         int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
 112
 113         generic_handle_irq(gpio_irq);
 114 }
 115
 116 static void ep93xx_gpio_irq_ack(struct irq_data *d)
 117 {
 118         int line = irq_to_gpio(d->irq);
 119         int port = line >> 3;
 120         int port_mask = 1 << (line & 7);
 121
 122         if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
 123                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 124                 ep93xx_gpio_update_int_params(port);
 125         }
 126
 127         writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 128 }
 129
 130 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
 131 {
 132         int line = irq_to_gpio(d->irq);
 133         int port = line >> 3;
 134         int port_mask = 1 << (line & 7);
 135
 136         if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
 137                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 138
 139         gpio_int_unmasked[port] &= ~port_mask;
 140         ep93xx_gpio_update_int_params(port);
 141
 142         writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 143 }
 144
 145 static void ep93xx_gpio_irq_mask(struct irq_data *d)
 146 {
 147         int line = irq_to_gpio(d->irq);
 148         int port = line >> 3;
 149
 150         gpio_int_unmasked[port] &= ~(1 << (line & 7));
 151         ep93xx_gpio_update_int_params(port);
 152 }
 153
 154 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
 155 {
 156         int line = irq_to_gpio(d->irq);
 157         int port = line >> 3;
 158
 159         gpio_int_unmasked[port] |= 1 << (line & 7);
 160         ep93xx_gpio_update_int_params(port);
 161 }
 162
 163 /*
 164  * gpio_int_type1 controls whether the interrupt is level (0) or
 165  * edge (1) triggered, while gpio_int_type2 controls whether it
 166  * triggers on low/falling (0) or high/rising (1).
 167  */
 168 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
 169 {
 170         const int gpio = irq_to_gpio(d->irq);
 171         const int port = gpio >> 3;
 172         const int port_mask = 1 << (gpio & 7);
 173         irq_flow_handler_t handler;
 174
 175         gpio_direction_input(gpio);
 176
 177         switch (type) {
 178         case IRQ_TYPE_EDGE_RISING:
 179                 gpio_int_type1[port] |= port_mask;
 180                 gpio_int_type2[port] |= port_mask;
 181                 handler = handle_edge_irq;
 182                 break;
 183         case IRQ_TYPE_EDGE_FALLING:
 184                 gpio_int_type1[port] |= port_mask;
 185                 gpio_int_type2[port] &= ~port_mask;
 186                 handler = handle_edge_irq;
 187                 break;
 188         case IRQ_TYPE_LEVEL_HIGH:
 189                 gpio_int_type1[port] &= ~port_mask;
 190                 gpio_int_type2[port] |= port_mask;
 191                 handler = handle_level_irq;
 192                 break;
 193         case IRQ_TYPE_LEVEL_LOW:
 194                 gpio_int_type1[port] &= ~port_mask;
 195                 gpio_int_type2[port] &= ~port_mask;
 196                 handler = handle_level_irq;
 197                 break;
 198         case IRQ_TYPE_EDGE_BOTH:
 199                 gpio_int_type1[port] |= port_mask;
 200                 /* set initial polarity based on current input level */
 201                 if (gpio_get_value(gpio))
 202                         gpio_int_type2[port] &= ~port_mask; /* falling */
 203                 else
 204                         gpio_int_type2[port] |= port_mask; /* rising */
 205                 handler = handle_edge_irq;
 206                 break;
 207         default:
 208                 return -EINVAL;
 209         }
 210
 211         __irq_set_handler_locked(d->irq, handler);
 212
 213         gpio_int_enabled[port] |= port_mask;
 214
 215         ep93xx_gpio_update_int_params(port);
 216
 217         return 0;
 218 }
 219
 220 static struct irq_chip ep93xx_gpio_irq_chip = {
 221         .name           = "GPIO",
 222         .irq_ack        = ep93xx_gpio_irq_ack,
 223         .irq_mask_ack   = ep93xx_gpio_irq_mask_ack,
 224         .irq_mask       = ep93xx_gpio_irq_mask,
 225         .irq_unmask     = ep93xx_gpio_irq_unmask,
 226         .irq_set_type   = ep93xx_gpio_irq_type,
 227 };
 228
 229 static void ep93xx_gpio_init_irq(void)
 230 {
 231         int gpio_irq;
 232
 233         for (gpio_irq = gpio_to_irq(0);
 234              gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
 235                 irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
 236                                          handle_level_irq);
 237                 set_irq_flags(gpio_irq, IRQF_VALID);
 238         }
 239
 240         irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
 241                                 ep93xx_gpio_ab_irq_handler);
 242         irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
 243                                 ep93xx_gpio_f_irq_handler);
 244         irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
 245                                 ep93xx_gpio_f_irq_handler);
 246         irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
 247                                 ep93xx_gpio_f_irq_handler);
 248         irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
 249                                 ep93xx_gpio_f_irq_handler);
 250         irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
 251                                 ep93xx_gpio_f_irq_handler);
 252         irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
 253                                 ep93xx_gpio_f_irq_handler);
 254         irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
 255                                 ep93xx_gpio_f_irq_handler);
 256         irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
 257                                 ep93xx_gpio_f_irq_handler);
 258 }
 259
 260
 261 /*************************************************************************
 262  * gpiolib interface for EP93xx on-chip GPIOs
 263  *************************************************************************/
 264 struct ep93xx_gpio_bank {
 265         const char      *label;
 266         int             data;
 267         int             dir;
 268         int             base;
 269         bool            has_debounce;
 270 };
 271
 272 #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
 273         {                                                       \
 274                 .label          = _label,                       \
 275                 .data           = _data,                        \
 276                 .dir            = _dir,                         \
 277                 .base           = _base,                        \
 278                 .has_debounce   = _debounce,                    \
 279         }
 280
 281 static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
 282         EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
 283         EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
 284         EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
 285         EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
 286         EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
 287         EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true),
 288         EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
 289         EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
 290 };
 291
 292 static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
 293                                     unsigned offset, unsigned debounce)
 294 {
 295         int gpio = chip->base + offset;
 296         int irq = gpio_to_irq(gpio);
 297
 298         if (irq < 0)
 299                 return -EINVAL;
 300
 301         ep93xx_gpio_int_debounce(irq, debounce ? true : false);
 302
 303         return 0;
 304 }
 305
 306 /*
 307  * Map GPIO A0..A7  (0..7)  to irq 64..71,
 308  *          B0..B7  (7..15) to irq 72..79, and
 309  *          F0..F7 (16..24) to irq 80..87.
 310  */
 311 static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 312 {
 313         int gpio = chip->base + offset;
 314
 315         if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
 316                 return -EINVAL;
 317
 318         return 64 + gpio;
 319 }
 320
 321 static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev,
 322         void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
 323 {
 324         void __iomem *data = mmio_base + bank->data;
 325         void __iomem *dir =  mmio_base + bank->dir;
 326         int err;
 327
 328         err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, 0);
 329         if (err)
 330                 return err;
 331
 332         bgc->gc.label = bank->label;
 333         bgc->gc.base = bank->base;
 334
 335         if (bank->has_debounce) {
 336                 bgc->gc.set_debounce = ep93xx_gpio_set_debounce;
 337                 bgc->gc.to_irq = ep93xx_gpio_to_irq;
 338         }
 339
 340         return gpiochip_add(&bgc->gc);
 341 }
 342
 343 static int ep93xx_gpio_probe(struct platform_device *pdev)
 344 {
 345         struct ep93xx_gpio *ep93xx_gpio;
 346         struct resource *res;
 347         void __iomem *mmio;
 348         int i;
 349         int ret;
 350
 351         ep93xx_gpio = kzalloc(sizeof(*ep93xx_gpio), GFP_KERNEL);
 352         if (!ep93xx_gpio)
 353                 return -ENOMEM;
 354
 355         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 356         if (!res) {
 357                 ret = -ENXIO;
 358                 goto exit_free;
 359         }
 360
 361         if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
 362                 ret = -EBUSY;
 363                 goto exit_free;
 364         }
 365
 366         mmio = ioremap(res->start, resource_size(res));
 367         if (!mmio) {
 368                 ret = -ENXIO;
 369                 goto exit_release;
 370         }
 371         ep93xx_gpio->mmio_base = mmio;
 372
 373         for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
 374                 struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i];
 375                 struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
 376
 377                 if (ep93xx_gpio_add_bank(bgc, &pdev->dev, mmio, bank))
 378                         dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
 379                                 bank->label);
 380         }
 381
 382         ep93xx_gpio_init_irq();
 383
 384         return 0;
 385
 386 exit_release:
 387         release_mem_region(res->start, resource_size(res));
 388 exit_free:
 389         kfree(ep93xx_gpio);
 390         dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, ret);
 391         return ret;
 392 }
 393
 394 static struct platform_driver ep93xx_gpio_driver = {
 395         .driver         = {
 396                 .name   = "gpio-ep93xx",
 397                 .owner  = THIS_MODULE,
 398         },
 399         .probe          = ep93xx_gpio_probe,
 400 };
 401
 402 static int __init ep93xx_gpio_init(void)
 403 {
 404         return platform_driver_register(&ep93xx_gpio_driver);
 405 }
 406 postcore_initcall(ep93xx_gpio_init);
 407
 408 MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
 409                 "H Hartley Sweeten <hsweeten@visionengravers.com>");
 410 MODULE_DESCRIPTION("EP93XX GPIO driver");
 411 MODULE_LICENSE("GPL");